Swimming pool device and method of making such device

ABSTRACT

A permanently installed in-ground swimming pool having vertical peripheral pool walls is disposed within an excavated area of ground such that the earthwall surrounding the pool walls slopes from ground level down to the lowermost portions of the pool walls, the space between the sloping earthwall and the vertical pool walls being filled with a lightweight, heat insulating, draining, fill material such as lightweight pellets of burned expanded clay, shale or the like. The ground outside of the pool walls should be excavated such that the slope of the downwardly inclining earthwall is about or somewhat less than the angle of repose of the ground.

United States Patent [1 1 Eliasson [451 Apr. 2, 1974 SWIMMING POOL DEVICE AND METHOD OF MAKING SUCH DEVICE 21 Appl. No.: 22,869

[30] Foreign Application Priority Data Putin ct al 52/169 X 3,374,491 3/1968 3,500,602 3/1970 Ucno 52/169 X 3,419,917 1/1969 Schankler 52/169 X FOREIGN PATENTS OR APPLICATIONS 54,799 3/1967 Germany 52/169 Primary Examiner-George H. Krizmanich [57] ABSTRACT A permanently installed in-ground swimming pool having vertical peripheral pool walls is disposed within an excavated area of ground such that the earthwall surrounding the pool walls slopes from ground level down to the lowermost portions of the pool walls, the space between the sloping earthwall and the vertical pool walls being filled with a lightweight, heat insulating, draining, fill material such as lightweight pellets of burned expanded clay, shale or the like. The ground outside of the pool walls should be excavated such that the slope of the downwardly inclining earthwall is about or somewhat less than the angle of repose of the ground.

2 Claims, 2 Drawing Figures Apr. 9, 1969 Sweden 4972/69 [52] US. Cl. 52/169, 52/742 [51] Int. Cl. E02d [58] Field of Search 52/169, 265, 742; 106/40 R; 4/172 [56] 7 References Cited UNITED STATES PATENTS 2,954,645 10/1960 Bennett 52/169 3,031,801 5/1962 Leuthesser.. 52/169 X 3,445,322 5/1969 Saiia et a1. 52/169 X 695,718 3/1902 Goodman 52/169 3,407,552 10/1968 Cassidy 52/169 1,360,170 11/1920 Allinson 52/169 X PATENIEDAPR 2 IBM I 3.800.487

Figure gawmd SWIMMING POOL DEVICE AND METHOD OF MAKING SUCH DEVICE The purpose of the present invention is to provide a far-reaching rationalization of the building of swimming pools by making special arrangements at the ground works and by simplifying the very building of the pool and to conduct this rationalization as far as possible with due consideration of the usual requirements as to the stability and strength and other quality properties of swimming pools. In other words, the invention has for one of its objects to provide, not withstanding the far-reaching rationalization, a fully reliable and sufficiently strong swimming pool.

A swimming pool device of the type defined is attained only if all the requirements stipulated are satistied at the same time.

The invention will be more fully described in the following, reference being made to the accompanying drawings in which FIGS. 1-2 illustrate one embodiment of the invention.

In the drawings:

FIG. 1 is a plan view of the swimming pool and the spaces beside and outside the poolwalls and the ground around the pool;

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1.

The nature of the device suggested by the present invention for swimming pools will appear from the following description of the method making such device.

The number of swimming pools being built all over the world has risen rapidly since the l940s. The methods for constructing these have also developped. At the beginning only conventional methodswere used, like concrete casting. Gradually there have been used new building methods as for example where the poolwalls are consisting of a support structure composed by steel, aluminium, wood panels etc. These materials are on their inside covered with a plastic liner as for example a vinyl liner. Another design is that the whole pool is moulded in one or many pieces of fiber-glass. All these new designs have the disadvantage that they have difficulties to withstand in an appropriate manner the earth pressure that exists on the outside of the poolwall. The result is that the pool cannot keep its shape and a collapse may occur. If a sufficient security should be obtained in this respect such strong structures must be used that the pool then will cost as much as a traditional concrete construction. During the last years a new type of pools have gained a great popularity and that is the so called type of above-ground pools.

These pools are designed to be placed on the ground and are consequently dimensioned without any thoughts on earth pressure but only considering the hydrostatic pressure from the pool water. These aboveground pools are usually fabricated with a simple steel structure with supporting walls of aluminium or other metals with a vinyl liner as the dense layer. These pools are very inexpensive compared with other in-ground pools". The cost is 30 percent or less. The technical standpoint today does not know any arrangement or method, that can make it possible to dig down an above-ground pool and convert it to an in-ground pool and on the same time secure sufficient strength against forces from the ground around the pool but avoiding a great rise in the cost. If, today, an above-ground pool is to be dug down completely or partly, there must be used complicated arrangements, as for example special structures or stands of wood or steel that prevent the earth pressure to reach the pool wall, or otherwise you must accept that the poolwalls are not maintaining their shape and are collapsing after a short time. In the United States there have been used among other things horizontal decks bridging from the poolwall to the ground and the space underneath the deck has not been filled. This is a very complicated design when using it in practice and entirely different from my invention, which completely eliminates the necessity of such decks etc. Today there is neither known any arrangement nor method, that can, concerning traditional in-ground pools, on the same time guarantee a simple construction and a sufficient security against earth pressure. The present invention makes this possible and makes it possible to convert above-ground pools to in-ground pools under full security concerning among other things the damageable earth pressure and on the same time to obtain very high cost reductions.

In connection with this invention the words swimming pool and pool are always referring to all types of pools made for bathing and swimming, however especially small such, that is 15 20 meters (-70 feet) of length and half the width and 2.5 meters (8 feet) deep and all sizes smaller. There are no limitations how small the dimensions can be. In point of principle the invention is valid for all pools with no limitations in the dimensions.

Referring now to the drawing, there is shown a generally rectangular in-ground swimming pool. The pool is illustrated as being disposed within an excavation in the ground 10 such that no substantial earth forces act against the sides or walls 12 of the pool. When making the excavation, the walls 11 thereof should be formed so that they will slope at an angle up to about the angle of repose of the ground. In a preferred embodiment, the earthwall I1 surrounding the walls 12 of the pool should slope at an angle of somewhat less than the angle of repose of the ground. Thus, the excavation is ordinarily made so that there will be no vertical earthwall surfaces. After the excavation is made, and the pool placed therein, the space 13 which is defined by the pool walls 12 and the sloping earthwall 11 is filled with a lightweightmaterial which exerts no earth pressure of importance on the pool walls 12. This feature of the present invention is very important since it enables the pool walls 12 to be designed so as to withstand primarily only the hydrostatic pressure from the pool water. In this regard, the fill material must have certain characteristics to satisfy the requirements of the present invention. For example, it should be as lightweight as possible, with a volume weight preferably not exceeding 30 lbs. per cubic foot (0.5 kg/dm) similarly, it should have sufficient compressive strength to make it possible to place, for example, slabs or tiles on top of the layer of fill material to withstand the traffic loads thereon. It should also be draining so as to avoid the creation of water and moisture pockets that accelerate the corrosion of the pool walls. Further, it should be chemically neutral to prevent corrosion of the pool walls, pipings, etc. Moreover, it should be heat insulating to prevent frost damage that can destroy the pool walls. And finally, it should have a low price.

For the purpose of the invention a so called lightweight aggregate is suitable to fulfil all the properties above mentioned. With a lightweight aggregate is then understood pellets or pieces of burnt expanded clay shale or slate etc. Besides, different types of so called foamed glass, especially in the form of pellets, can be used. Also different types of granulated plastic material can be considered.

With this invention another problem is also solved in the connection with swimming pools. It is often a desire to have a simple access to piping, underwater light etc. When using for example lightweight aggregate, which at pipes, lights, inlets, etc. preferrably should be bound with e.g. cement, it is very easy to obtain this aim.

It is already known in connection with fiberglass pools to placea mineral wool slab vertically outside the poolwall to eliminate the risk for damages on the poolwalls caused by stones etc. in the refill of ordinary material. This slab has however no capability to withstand the earth pressure, to be draining etc. My invention solves also the above mentioned problem to protect the poolwalls from being destroyed this way. It is further known to use, in connection with foundation structures of ordinary house constructions, a heat insulation material, not a lightweight aggregate however to diminish the downward movement of the frost. in the known cases it has been ordinary concrete constructions in question and not wall structures like the special swimming pool design in this invention. The wall construction in my invention is, as mentioned above, primarily designed to withstand forces from the water pressure on the inside of the wall, so in my invention the important is to reduce the direct earth pressure.

As an example on the economic gain that is made with this invention, it could be mentioned that for example an oval pool measuring 4.5 X 9 meters (15 feetX30 feet) and a maximum depth of 2.5 meters (8 feet), made of concrete, in a normal case costs about US. $3,000.- (not including mechanical and electrical equipment and piping). If using this invention the corresponding cost would be about $1,500.- or less. Then has been calculated with a pool of above-ground type, that has been dug down, and around it has been refilled with for example a lightweight aggregate.

What I claim and desire to secure by Letters Patent 1. A permanently installed in-ground swimming pool comprising,

a pool having vertical walls, said walls being designed to withstand hydrostatic pressure generated by water in said pool when said pool is filled with water;

an excavation in the ground for receiving said pool, said excavation having earthwalls which surround said vertical walls of said pool and which are spaced therefrom, said earthwalls being inclined at an angle of up to about the angle of repose of the ground; and

a heat insulating, draining and chemically neutral filler material disposed on the inclined earthwalls of said excavation and filling the space between said earthwalls and said vertical pool walls, said filler material being selected from the group consisting of burnt expanded clay, shale, slate, foamed glass and granulated plastic, and said filler material having a density of up to about 30 pounds per cubic foot.

2. A method of installing an in-ground swimming pool, which comprises:

making an excavation in the ground for receiving a pool, said excavation having side walls and a bottom;

forming an incline on the side walls of the excavation such that the angle of inclination, when measured from ground level to the bottom of the excavation, is up to about the natural angle of repose of the ground;

placing a pool on the bottom of the excavation, the pool having vertical side walls such that the vertical side walls of the pool and the inclined walls of the excavation define a space around the pool; and

filling the space around the pool with a heat insulating, draining and chemically neutral filler material having a density of up to about 30 pounds per cubic foot and having sufficient compressive strength to withstand traffic loads on the ground surface, said filler material being selected from the group consisting of burnt expanded clay, shale, slate, foamed glass and granulated plastic. 

1. A permanently installed in-ground swimming pool comprising, a pool having vertical walls, said walls being designed to withstand hydrostatic pressure generated by water in said pool when said pool is filled with water; an excavation in the ground for receiving said pool, said excavation having earthwalls which surround said vertical walls of said pool and which are spaced therefrom, said earthwalls being inclined at an angle of up to about the angle of repose of the ground; and a heat insulating, draining and chemically neutral filler material disposed on the inclined earthwalls of said excavation and filling the space between said earthwalls and said vertical pool walls, said filler material being selected from the group consisting of burnt expanded clay, shale, slate, foamed glass and granulated plastic, and said filler material having a density of up to about 30 pounds per cubic foot.
 2. A method of installing an in-ground swimming pool, which comprises: making an excavation in the ground for receiving a pool, said excavation having side walls and a bottom; forming an incline on the side walls of the excavation such that the angle of inclination, when measured from ground level to the bottom of the excavation, is up to about the natural angle of repose of the ground; placing a pool on the bottom of the excavation, the pool having vertical side walls such thaT the vertical side walls of the pool and the inclined walls of the excavation define a space around the pool; and filling the space around the pool with a heat insulating, draining and chemically neutral filler material having a density of up to about 30 pounds per cubic foot and having sufficient compressive strength to withstand traffic loads on the ground surface, said filler material being selected from the group consisting of burnt expanded clay, shale, slate, foamed glass and granulated plastic. 